Parallel framework variable-speed electric drive assembly

Abstract

The utility model discloses a parallel framework variable-speed electric drive assembly. A power output sleeve and a middle transmission sleeve which can rotate relative to a main shaft, and a power connecting sleeve and a sliding shifting fork sleeve which synchronously rotate with the main shaft are sequentially sleeved on the main shaft towards the direction far away from a motor shaft, or an internal spline of the shifting fork sleeve is combined with a high-speed gear external spline; or the shifting fork sleeve combination teeth are combined with the low-speed gear combination teeth. By adopting the variable-speed electric drive assembly with the parallel structure, through ingenious matching of the power output sleeve, the middle transmission sleeve, the power connecting sleeve, the low-speed gear transmission sleeve and the shifting fork sleeve which are almost arranged in parallel, compared with an existing low-cost electric drive system, on the premise that the reduction ratio is guaranteed, at least one stage of speed reduction transmission is omitted, and the transmission efficiency is improved. The transmission efficiency is effectively improved, the overall structure is more compact, and the overall appearance size is reduced, so that the requirement for the installation space is lowered, and the applicability is better.

Description

Technical Field

[0001] The utility model relates to the technical field of electric drive systems, and in particular to a parallel-structure variable-speed electric drive assembly. Background Art

[0002] The operation of electric vehicles depends first on the electric drive system. The electric drive system has achieved a deep integration of mechanical and electric drive power components. It is the core component of driving and all the devices needed to provide power for electric vehicles. The electric drive system is mainly composed of four parts: drive motor, transmission, power converter and controller. Its performance and efficiency directly affect the power, economy and comfort of electric vehicles. The size and weight of the drive motor and transmission will also affect the overall efficiency of electric vehicles. The power converter and controller are closely related to the safe and reliable operation of electric vehicles.

[0003] Although the electric drive system equipped with only a reduction transmission can make the torque output generated by the electric motor direct and smooth, it cannot take into account the power and economy of pure electric vehicles at the same time. This is because the drive motor cannot be at a high-efficiency working point in most working conditions during driving, especially at the highest or lowest vehicle speed and under low load conditions. Due to the large reduction transmission ratio, there is no room for improvement after the speed reaches the limit, causing the electric vehicle to be at a relatively high speed critical point in the cruising state. The speed is restricted, and the efficiency generally drops below 60-70%. The power loss is large, the high-speed economy is not high, the vehicle's power, economy and comfort are poor, and the on-board electric energy is seriously wasted, which reduces the driving range. In addition, the electric drive system equipped with only a reduction transmission structure is not conducive to the use of high-efficiency and lightweight drive motors.

[0004] Compared with electric drive systems equipped with gearboxes, electric drive systems equipped with gearboxes have less power output loss, can provide higher driving torque in the constant torque area, and can provide higher speed in the constant power area, and can also achieve high torque and high efficiency under low speed and heavy load conditions. Therefore, even low-cost electric drive systems have begun to generally add manual transmission mechanisms.

[0005] However, please refer to the Chinese utility model patent publication number CN214189988U. Due to structural design problems, the manual transmission mechanism of the existing low-cost electric drive system requires at least four-stage reduction transmission in the low-speed gear to achieve an ideal reduction ratio. The large number of transmission stages not only leads to less than ideal transmission efficiency, but also a larger overall size and higher requirements for installation space.

[0006] Solving the above problems has become a top priority. Utility Model Content

[0007] In order to solve the technical problems that the manual speed change mechanism of the existing low-cost electric drive system has a large number of transmission stages, resulting in unsatisfactory transmission efficiency and large external dimensions, the utility model provides a parallel structure speed change electric drive assembly.

[0008] The technical solution is as follows:

[0009] The first aspect of the present application relates to a parallel-structure variable-speed electric drive assembly, including a motor, a power output mechanism and a main shaft that rotates synchronously with the motor shaft of the motor, the inner end of the main shaft being coaxially connected to the outer end of the motor shaft, the main shaft being sequentially provided with a power output sleeve and an intermediate transmission sleeve that can rotate relative to the main shaft, and a power coupling sleeve that rotates synchronously with the main shaft in a direction away from the motor shaft, the power output sleeve being capable of transmitting power to the power output mechanism, the intermediate transmission sleeve being synchronously rotated with the power output sleeve, and having a secondary driven tooth formed integrally therewith, the power coupling sleeve being spline-matched with a shift fork sleeve that can slide along its axial direction, the intermediate transmission sleeve being formed with a high-speed gear external spline at one end close to the power coupling sleeve, and the high-speed The outer gear spline is matched with the inner spline of the shift fork sleeve formed on the inner circumference of the shift fork sleeve, and the intermediate transmission sleeve is provided with a low-speed gear transmission sleeve that can rotate relative to it, and the low-speed gear transmission sleeve is formed with a primary driving tooth whose outer diameter is smaller than the secondary driven tooth. A secondary shaft parallel to the main shaft is provided beside the main shaft, and the secondary shaft is formed with a primary driven tooth meshing with the primary driving tooth and a secondary driving tooth meshing with the secondary driven tooth. The low-speed gear transmission sleeve is located on the side of the secondary driven tooth close to the power connection sleeve, and the end of the low-speed gear transmission sleeve away from the secondary driven tooth protrudes from the high-speed gear outer spline, and a low-speed gear coupling tooth is formed on its inner circumference, and a shift fork sleeve coupling tooth matched with the low-speed gear coupling tooth is formed on the outer circumference of one end of the shift fork sleeve close to the motor;

[0010] When the fork sleeve is slid to make the inner spline of the fork sleeve engage with the outer spline of the high-speed gear, the fork sleeve engaging teeth are separated from the low-speed gear engaging teeth; when the fork sleeve is slid to make the fork sleeve engaging teeth engage with the low-speed gear engaging teeth, the inner spline of the fork sleeve is separated from the outer spline of the high-speed gear.

[0011] By adopting the above parallel structure speed-changing electric drive assembly, through the ingenious coordination of the power output sleeve, intermediate transmission sleeve, power connection sleeve, low-speed gear transmission sleeve and shift fork sleeve which are almost arranged in parallel, under the premise of ensuring the reduction ratio, the low-speed gear only needs at least three levels of reduction transmission, and the power can be transmitted to the power output mechanism through the power output sleeve. Compared with the existing low-cost electric drive system, at least one level of reduction transmission is saved, which not only effectively improves the transmission efficiency, but also makes the overall structure more compact and reduces the overall external dimensions, thereby reducing the requirements for installation space and having better applicability.

[0012] In some embodiments, the power output mechanism includes a differential, power output teeth formed on a power output sleeve, and an intermediate shaft parallel to the main shaft, an intermediate shaft input gear synchronously rotatingly mounted on the intermediate shaft and meshing with the power output teeth, an intermediate shaft output teeth meshing with the differential input gear of the differential formed on the intermediate shaft, a diameter of the intermediate shaft input gear is greater than a diameter of the power output teeth, and a diameter of the differential input gear is greater than a diameter of the intermediate shaft output teeth.

[0013] In some embodiments, the power output mechanism includes a driven sprocket, a chain, and active chain teeth formed on the power output sleeve, and the active chain teeth can drive the driven sprocket to rotate through the chain.

[0014] In some embodiments, the low-speed gear transmission sleeve includes a transmission sleeve main body and a transmission sleeve end portion locked on the transmission sleeve main body away from the motor by multiple bolts, the transmission sleeve main body includes a main body support section that can be relatively rotatably mounted on the intermediate transmission sleeve and a main body expansion section expanded at the main body support section away from the motor, the primary active tooth is formed on the outer circumferential surface of the main body support section, an end face bearing is arranged between the end of the main body support section away from the main body expansion section and the adjacent side wall of the secondary driven tooth, a deep groove ball bearing is arranged between the inner circumferential surface of the main body expansion section and the outer circumferential surface of the intermediate transmission sleeve, the low-speed gear combining tooth is formed on the inner circumferential surface of the transmission sleeve end portion, and the end of the transmission sleeve close to the motor presses the outer ring of the deep groove ball bearing inward.

[0015] In some embodiments, the end of the intermediate transmission sleeve away from the motor is reduced in diameter to form a bearing mounting sink that is compatible with the deep groove ball bearing, the inner ring of the deep groove ball bearing is press-fitted into the bearing mounting sink with an interference fit, and the end of the bearing mounting sink away from the motor is reduced in diameter to form the high-speed gear external spline.

[0016] In some embodiments, one end of the intermediate transmission sleeve away from the bearing mounting sink is spline-matched with the power output sleeve, and the middle part of the intermediate transmission sleeve is rotatably mounted on the main shaft through a needle bearing.

[0017] In some embodiments, a bolt locking seat corresponding to each bolt is protruded on the outer circumferential surface of the expanded diameter section of the main body away from one end of the supporting section of the main body, and a bolt mounting seat corresponding to each bolt locking seat is protruded on the outer circumferential surface of the end of the transmission sleeve, and each bolt is locked on the corresponding bolt locking seat after passing through the corresponding bolt mounting seat. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the structure of Embodiment 1 when it is in low gear;

[0019] Figure 2 This is a schematic diagram of the structure of Example 1 when it is in high gear;

[0020] Figure 3 This is a schematic diagram of the structure of Embodiment 2 when it is in low gear;

[0021] Figure 4 It is a schematic diagram of the structure of Example 2 when it is in high gear. DETAILED DESCRIPTION

[0022] The utility model is further described below in conjunction with embodiments and drawings.

[0023] Embodiment 1:

[0024] like Figure 1 and Figure 2 As shown, a parallel-structure variable-speed electric drive assembly mainly includes a motor 1 and a speed change system, wherein the speed change system includes a main shaft 2, a gear shift transmission mechanism and a power output mechanism. The main shaft 2 rotates synchronously with the motor shaft 1a of the motor 1. Specifically, the inner end of the main shaft 2 is coaxially connected with the outer end of the motor shaft 1a. In this embodiment, the outer end of the motor shaft 1a is recessed to form a spline groove, and the inner end spline of the main shaft 2 is fittedly inserted into the spline groove of the outer end of the motor shaft 1a, which not only ensures the synchronous rotation of the motor shaft 1a and the main shaft 2, but also is simple, reliable and easy to assemble.

[0025] The gear shift transmission mechanism includes a power output sleeve 3, an intermediate transmission sleeve 4 and a power connecting sleeve 5 which are sequentially mounted on the main shaft 2 in a direction away from the motor shaft 1a, wherein the power output sleeve 3 and the intermediate transmission sleeve 4 can be mounted on the main shaft 2 so as to rotate relative to each other, and the power connecting sleeve 5 is mounted on the main shaft 2 so as to rotate synchronously.

[0026] The power output sleeve 3 can transmit power to the power output mechanism, the intermediate transmission sleeve 4 rotates synchronously with the power output sleeve 3, and the intermediate transmission sleeve 4 is integrally formed with a secondary driven tooth 4a, the power connection sleeve 5 is spline-matched with a shift fork sleeve 6 that can slide along its axial direction, and the intermediate transmission sleeve 4 is formed with a high-speed gear external spline 4b at one end close to the power connection sleeve 5, and the high-speed gear external spline 4b is adapted to the shift fork sleeve internal spline 6a formed on the inner circumference of the shift fork sleeve 6, that is, the shift fork sleeve internal spline 6a can be combined or separated with the high-speed gear external spline 4b. It should be pointed out that, except for the spline length, the spline parameters of the high-speed gear external spline 4b are exactly the same as those of the external spline on the outer circumference of the power connection sleeve 5. Therefore, while the shift fork sleeve internal spline 6a maintains spline matching with the external spline on the outer circumference of the power connection sleeve 5, it can also be spline matched with the high-speed gear external spline 4b.

[0027] The intermediate transmission sleeve 4 is provided with a low-speed gear transmission sleeve 7 which can rotate relative to the intermediate transmission sleeve 4. The low-speed gear transmission sleeve 7 is formed with a primary driving tooth 7a11 whose outer diameter is smaller than the secondary driven tooth 4a. A secondary shaft 8 parallel to the primary shaft 2 is provided. The secondary shaft 8 is formed with a primary driven tooth 8a meshing with the primary driving tooth 7a11 and a secondary driving tooth 8b meshing with the secondary driven tooth 4a, so as to realize a two-stage large reduction ratio reduction transmission on the secondary shaft 8. The low-speed gear transmission sleeve 7 is located on the side of the secondary driven tooth 4a close to the power connection sleeve 5. The end of the low-speed gear transmission sleeve 7 away from the secondary driven tooth 4a protrudes from the high-speed gear external spline 4b, and a low-speed gear coupling tooth 7b1 is formed on its inner circumference. The outer circumference of the fork sleeve 6 close to the motor 1 is formed with a fork sleeve coupling tooth 6b adapted to the low-speed gear coupling tooth 7b1, that is, the fork sleeve coupling tooth 6b can be combined with or separated from the low-speed gear coupling tooth 7b1.

[0028] When the sliding fork sleeve 6 causes the inner spline 6a of the fork sleeve to engage with the high-speed gear outer spline 4b, the fork sleeve engaging teeth 6b separate from the low-speed gear engaging teeth 7b1, and high-speed gear transmission is performed; when the sliding fork sleeve 6 causes the fork sleeve engaging teeth 6b to engage with the low-speed gear engaging teeth 7b1, the inner spline 6a of the fork sleeve separates from the high-speed gear outer spline 4b, and low-speed gear transmission is performed.

[0029] Therefore, through the ingenious coordination of the power output sleeve 3, the intermediate transmission sleeve 4, the power connection sleeve 5, the low-speed gear transmission sleeve 7 and the shift fork sleeve 6 which are arranged almost in parallel, under the premise of ensuring the reduction ratio, the low-speed gear only needs at least three levels of reduction transmission to transmit the power to the power output mechanism through the power output sleeve 3. Compared with the existing low-cost electric drive system, at least one level of transmission is saved, which not only effectively improves the transmission efficiency, but also makes the overall structure more compact and reduces the overall external dimensions, thereby reducing the requirements for installation space and having better applicability.

[0030] Furthermore, the low-speed gear transmission sleeve 7 includes a transmission sleeve main body 7a and a transmission sleeve end 7b locked at one end of the transmission sleeve main body 7a away from the motor 1 by a plurality of bolts 7c. The plurality of bolts 7c are evenly distributed along the circumferential direction, which can effectively improve the reliability of the connection between the transmission sleeve main body 7a and the transmission sleeve end 7b.

[0031] Furthermore, a bolt locking seat 7a21 corresponding to each bolt 7c is protruded on the outer peripheral surface of the main body expansion section 7a2 away from the end of the main body support section 7a1, and a bolt mounting seat 7b1 corresponding to each bolt locking seat 7a21 is protruded on the outer peripheral surface of the transmission sleeve end 7b. After each bolt 7c passes through the corresponding bolt mounting seat 7b1, it is locked on the corresponding bolt locking seat 7a21, that is, the bolt 7c is threadedly matched with the threaded hole on the bolt locking seat 7a21, and the bolt mounting seat 7b1 is provided with a through hole adapted to the bolt 7c, which can allow the screw portion of the bolt 7c to pass through but not the head of the bolt 7c to pass through. Therefore, when the screw portion of the bolt 7c is tightened in the threaded hole on the bolt locking seat 7a21, the transmission sleeve main body 7a and the transmission sleeve end 7b are tightened into one.

[0032] The transmission sleeve body 7a includes a main body support section 7a1 which can be relatively rotatably mounted on the intermediate transmission sleeve 4 and a main body expansion section 7a2 which is expanded and formed at one end of the main body support section 7a1 away from the motor 1, that is, the inner diameter and outer diameter of the main body expansion section 7a2 are both larger than the inner diameter and outer diameter of the main body support section 7a1. The primary active tooth 7a11 is formed on the outer peripheral surface of the main body support section 7a1, and an end bearing 13 is arranged between the end of the main body support section 7a1 away from the main body expansion section 7a2 and the adjacent side wall of the secondary driven tooth 4a. At the same time, a deep groove ball bearing 14 is arranged between the inner peripheral surface of the main body expansion section 7a2 and the outer peripheral surface of the intermediate transmission sleeve 4, so that the low-speed gear transmission sleeve 7 and the intermediate transmission sleeve 4 do not interfere with each other, can rotate freely, and ensure the reliability of the installation of the low-speed gear transmission sleeve 7. The low-speed gear engaging teeth 7b1 are formed on the inner circumferential surface of the transmission sleeve end 7b. The end of the transmission sleeve end 7b close to the motor 1 presses the outer ring of the deep groove ball bearing 14 inwardly, thereby ensuring the reliability of the installation of the deep groove ball bearing 14.

[0033] The end of the intermediate transmission sleeve 4 away from the motor 1 is reduced in diameter to form a bearing installation sink 4c that matches the deep groove ball bearing 14. The inner ring of the deep groove ball bearing 14 is press-fitted into the bearing installation sink 4c with an interference fit, further improving the reliability of the assembly of the deep groove ball bearing 14. At the same time, the end of the bearing installation sink 4c away from the motor 1 is reduced in diameter and processed with a high-speed gear external spline 4b, that is, the outer peripheral surface of the high-speed gear external spline 4b is lower than the groove bottom of the bearing installation sink 4c close to the motor 1, avoiding interference problems when assembling the deep groove ball bearing 14.

[0034] Furthermore, one end of the intermediate transmission sleeve 4 away from the bearing mounting sinker 4c is splined with the power output sleeve 3, ensuring the synchronous rotation of the power output sleeve 3 and the intermediate transmission sleeve 4. At the same time, the middle part of the intermediate transmission sleeve 4 can be rotatably mounted on the main shaft 2 through a needle bearing 15, which is simple and reliable, ensuring the reliability of the assembly of the intermediate transmission sleeve 4 and the smoothness of its rotation.

[0035] In this embodiment, the power output mechanism includes a differential 10, a power output tooth 3a formed on the power output sleeve 3, and an intermediate shaft 9 parallel to the main shaft 2. An intermediate shaft input gear 9a is synchronously rotated on the intermediate shaft 9 and meshes with the power output tooth 3a. An intermediate shaft output tooth 9b is formed on the intermediate shaft 9 and meshes with the differential input gear 10a of the differential 10. The diameter of the intermediate shaft input gear 9a is larger than the diameter of the power output tooth 3a, and the diameter of the differential input gear 10a is larger than the diameter of the intermediate shaft output tooth 9b.

[0036] The high-speed gear power transmission route of this embodiment (at this time, the inner spline 6a of the fork sleeve is combined with the high-speed gear outer spline 4b):

[0037] Motor shaft 1a→main shaft 2→power connection sleeve 5→shift fork sleeve 6→intermediate transmission sleeve 4→power output sleeve 3→power output gear 3a→intermediate shaft input gear 9a→intermediate shaft 9→differential input gear 10a→differential 10, and power is transmitted to the drive shaft through the differential 10.

[0038] The low-speed gear power transmission route of this embodiment (at this time, the fork sleeve combining tooth 6b is combined with the low-speed gear combining tooth 7b1):

[0039] Motor shaft 1a→main shaft 2→power connection sleeve 5→shift fork sleeve 6→low speed gear transmission sleeve 7→counter shaft 8→intermediate transmission sleeve 4→power output sleeve 3→power output gear 3a→intermediate shaft input gear 9a→intermediate shaft 9→differential input gear 10a→differential 10, and transmit power to the drive shaft through the differential 10.

[0040] Embodiment 2:

[0041] See also Figure 3 and Figure 4 The main structure of this embodiment is exactly the same as that of embodiment 1, and the difference lies in the power output mechanism.

[0042] In this embodiment, the power output mechanism includes a driven sprocket 11 , a chain 12 , and active chain teeth 3 b formed on the power output sleeve 3 . The active chain teeth 3 b can drive the driven sprocket 11 to rotate through the chain 12 .

[0043] The high-speed gear power transmission route of this embodiment (at this time, the inner spline 6a of the fork sleeve is combined with the high-speed gear outer spline 4b):

[0044] Motor shaft 1a→main shaft 2→power connection sleeve 5→shift fork sleeve 6→intermediate transmission sleeve 4→power output sleeve 3→driving chain tooth 3b→chain 12→driven sprocket 11, and the power is transmitted to the driving shaft through the driven sprocket 11.

[0045] The low-speed gear power transmission route of this embodiment (at this time, the fork sleeve combining tooth 6b is combined with the low-speed gear combining tooth 7b1):

[0046] Motor shaft 1a→main shaft 2→power connection sleeve 5→shift fork sleeve 6→low speed gear transmission sleeve 7→counter shaft 8→intermediate transmission sleeve 4→power output sleeve 3→driving chain tooth 3b→chain 12→driven sprocket 11, and the power is transmitted to the driving shaft through the driven sprocket 11.

[0047] Finally, it should be noted that the above description is only a preferred embodiment of the present invention. Under the guidance of the present invention, ordinary technicians in this field can make a variety of similar expressions without violating the purpose and claims of the present invention, and such changes fall within the scope of protection of the present invention.

Claims

1. A parallel-structure variable-speed electric drive assembly, comprising a motor (1), a power output mechanism, and a main shaft (2) that rotates synchronously with a motor shaft (1a) of the motor (1), wherein the inner end of the main shaft (2) is coaxially connected to the outer end of the motor shaft (1a), and characterized in that: The main shaft (2) is provided with a power output sleeve (3) and an intermediate transmission sleeve (4) which are both rotatable relative to the main shaft (2) and a power connection sleeve (5) which rotates synchronously with the main shaft (2) in sequence in a direction away from the motor shaft (1a). The power output sleeve (3) is capable of transmitting power to a power output mechanism. The intermediate transmission sleeve (4) rotates synchronously with the power output sleeve (3) and is integrally formed with a secondary driven tooth (4a). The power connection sleeve (5) is provided with a shift fork sleeve (6) which is slidable along its axial direction in a spline-matched manner. The intermediate transmission sleeve (4) is provided with a high-speed gear external spline (4b) at one end close to the power connection sleeve (5). The high-speed gear external spline (4b) is matched with the shift fork sleeve internal spline (6a) formed on the inner circumferential surface of the shift fork sleeve (6). The intermediate transmission sleeve (4) is provided with a shift fork sleeve internal spline (6a) which is rotatable relative to the shift fork sleeve (6). A low-speed gear transmission sleeve (7), on which a primary driving tooth (7a11) having an outer diameter smaller than that of the secondary driven tooth (4a) is formed, a secondary shaft (8) parallel to the main shaft (2) is provided next to the main shaft, on which a primary driven tooth (8a) meshing with the primary driving tooth (7a11) and a secondary driving tooth (8b) meshing with the secondary driven tooth (4a) are formed, the low-speed gear transmission sleeve (7) is located on a side of the secondary driven tooth (4a) close to the power connection sleeve (5), and an end of the low-speed gear transmission sleeve (7) away from the secondary driven tooth (4a) protrudes from the high-speed gear external spline (4b), and a low-speed gear coupling tooth (7b1) is formed on its inner circumferential surface, and a shift fork sleeve coupling tooth (6b) matched with the low-speed gear coupling tooth (7b1) is formed on the outer circumferential surface of one end of the shift fork sleeve (6) close to the motor (1); When the fork sleeve (6) is slid to make the inner spline (6a) of the fork sleeve engage with the outer spline (4b) of the high-speed gear, the fork sleeve engaging teeth (6b) are separated from the low-speed gear engaging teeth (7b1); when the fork sleeve (6) is slid to make the inner spline (6a) of the fork sleeve engage with the outer spline (4b) of the high-speed gear, the fork sleeve engaging teeth (6b) are separated from the outer spline (4b) of the high-speed gear.

2. The parallel-structure variable-speed electric drive assembly according to claim 1, characterized in that: The power output mechanism comprises a differential (10), a power output tooth (3a) formed on a power output sleeve (3), and an intermediate shaft (9) parallel to the main shaft (2); an intermediate shaft input gear (9a) is synchronously rotated and meshed with the power output tooth (3a); an intermediate shaft output tooth (9b) is formed on the intermediate shaft (9) and meshed with the differential input gear (10a) of the differential (10); the diameter of the intermediate shaft input gear (9a) is greater than the diameter of the power output tooth (3a); and the diameter of the differential input gear (10a) is greater than the diameter of the intermediate shaft output tooth (9b).

3. The parallel-structure variable-speed electric drive assembly according to claim 1, characterized in that: The power output mechanism comprises a driven sprocket (11), a chain (12) and active chain teeth (3b) formed on a power output sleeve (3); the active chain teeth (3b) can drive the driven sprocket (11) to rotate through the chain (12).

4. The parallel-structure variable-speed electric drive assembly according to claim 1, characterized in that: The low-speed gear transmission sleeve (7) comprises a transmission sleeve main body (7a) and a transmission sleeve end (7b) locked to the end of the transmission sleeve main body (7a) away from the motor (1) by a plurality of bolts (7c); the transmission sleeve main body (7a) comprises a main body support section (7a1) which is relatively rotatably sleeved on the intermediate transmission sleeve (4) and a main body expansion section (7a2) which is expanded and formed at the end of the main body support section (7a1) away from the motor (1); the primary active tooth (7a11) is formed on the main body support section (7a1 ), an end face bearing (13) is arranged between one end of the main body support section (7a1) away from the main body expansion section (7a2) and the adjacent side wall of the secondary driven tooth (4a), a deep groove ball bearing (14) is arranged between the inner circumference of the main body expansion section (7a2) and the outer circumference of the intermediate transmission sleeve (4), the low speed gear coupling tooth (7b1) is formed on the inner circumference of the transmission sleeve end (7b), and the end of the transmission sleeve end (7b) close to the motor (1) presses the outer ring of the deep groove ball bearing (14) inwardly.

5. The parallel-structure variable-speed electric drive assembly according to claim 4, characterized in that: The end of the intermediate transmission sleeve (4) away from the motor (1) is reduced in diameter to form a bearing mounting sink (4c) matched with the deep groove ball bearing (14); the inner ring of the deep groove ball bearing (14) is press-fitted into the bearing mounting sink (4c) with an interference fit; and the end of the bearing mounting sink (4c) away from the motor (1) is reduced in diameter to form the high-speed gear external spline (4b).

6. The parallel-structure variable-speed electric drive assembly according to claim 5, characterized in that: One end of the intermediate transmission sleeve (4) away from the bearing mounting sink (4c) is spline-matched with the power output sleeve (3), and the middle part of the intermediate transmission sleeve (4) is rotatably mounted on the main shaft (2) via a needle bearing (15).

7. The parallel-structure variable-speed electric drive assembly according to claim 4, characterized in that: The outer peripheral surface of the main body expansion section (7a2) away from the main body support section (7a1) is protruded with a bolt locking seat (7a21) corresponding to each bolt (7c) one by one. The outer peripheral surface is protruded with bolt mounting seats which are respectively fitted with the bolt locking seats (7a21) one by one. Each bolt (7c) passes through a corresponding bolt mounting seat and is locked on a corresponding bolt locking seat (7a21).

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